Authors: Maxim Kramar (University of Hawaii at Manoa), Haosheng Lin (University of Hawaii at Manoa)

The coronal magnetic field is important driving force for transient coronal and space weather phenomena. The information about the magnetic field is encoded in spectropolarimetric properties of the magnetically sensitive coronal emission lines (such as Fe XIII 1074.7 nm forbidden line). However, a direct measurement of the magnetic field from these observations is not straightforward because of the data are essentially the emission integrated over the optically thin and non-homogenious coronal plasma. Therefore, the vector tomography inversion method should be applied to reconstruct the magnetic field in 3D.

The Daniel K. Inouye Solar Telescope (DKIST) instruments, such as Diffraction-Limited Near-IR Spectropolarimeter (DL-NIRSP) and Cryogenic Near-IR Spectro-Polarimeter (Cryo-NIRSP) will allow us to observe all polarization states of such coronal lines. However it spatial coverage is rather limited. Additionally, the Updated Coronal Multichannel Polarimeter (UCoMP) can regularly observe the linear (LP) polarization of the Fe XIII 1074.7 nm forbidden line with full spatial coverage up to about 2 Rsun.

We will demonstrate the use of the vector tomography inversion method with these observations and its quantitative validation. A Predictive Science MHD model was used as a ground truth by synthesizing the polarization observations of the Fe XIII line.